When I first met the sr. onco surgeon he described my colorectal cancer as 'malignant', "2nd or 3rd stage', 'definitely not stage one'. I remember I had started to cry because these words sacred me. Had I been equipped with some basic knowledge, I would happen been more in control of the situation and not killed myself with worry.
Thus I am sharing from vital technical information that every cancer patient and care giver and family members need to understand. I have not written this article.
The source of the article is Cancer Research UK
What Staging is
The stage of cancer means how big it is and whether it has spread. This is important because treatment is often based on the stage of cancer.
The tests and scans you have when diagnosing you cancer gives information about the clinical stage. During surgery the doctor finds out more about the stage. The tissue the surgeon removes, including lymph nodes, is carefully examined in the laboratory. These results are combined with the clinical stage to give a pathological stage. This is more accurate than the clinical stage. The pathological stage maybe different from the clinical stage. For example, the surgeon may find the cancer is more advanced than it looked in the scans. On staging your report, you may see a lower case letter (c or p) written before the stage. This shows that it is the clinical or pathological stage.
Many doctors in the UK stage bowel cancers using the 5th version of the TNM staging system, or the number staging system. These staging systems are used across the world. Some doctors use the Dukes' staging system - which I will describe later.
TNM Staging of Bowel Cancer
TNM stands for Tumour, Nodes, Metastases. This staging system describes the size of a primary tumour (T), whether any lymph nodes contain cancer cells (N), and whether the cancer has spread to another part of the body (M).
There are 4 stages of tumour size in bowel cancer
1. T1 means the tumour is only in the inner layer of the bowel
2. T2 means tumour has grown into the muscle layer of the bowel wall
3. T3 means tumour has grown into the outer lining of the bowel wall
4. T4 means the tumour has grown through the outer lining of the bowel wall. It may have grown into another part of the bowel, or other nearby organs or structures. Or it may have broken through thr membrane covering the outside of the bowel ( the peritoneum)
There are 3 possible stages whether cancer cells are in the lymph nodes
1. N0 means there are no lymph nodes containing cancer cells
2. N1 means that 1to 3 lymph nodes close to bowel contain cancer cells
3. N2 means there are cancer cells in 4 or more nearby lymph nodes
There are 2 stages of cancer spread (metastasis)
1. M0 means cancer has not spread to other organs
2. M1 means the cancer has spread to other parts of the body
Your doctor puts T,N and M results together to you your stage. For example, you see a bowel cancer described as T2, N0, M0. This means
- The tumour has grown into the muscle layer of the bowel wall
- There is no evidence of cancer cells in the lymph nodes
- No evidence of spread to other parts of the body
Number Stages of Bowel Cancer
The number system uses TNM stages to group bowel cancers. There are 5 main stages in this system.
Stage 0 or Carcinoma in Situ (CIS)
If you are told to have CIS or stage0 colorectal cancer, there are cancer cells in your inner bowel lining. But the cancer cells are cintained within this lining. So there is very little risk of any cancer cells having to spread.
Stage 1 Bowel Cancer
The cancer has grown through the inner lining of the bowel, or into the muscle wall, but no further. There is no cancer in the lymph nodes (in TNM staging, this is the same as T1, N0, M0)
Stage 2 Bowel Cancer
This stage is divided into 2a and 2b
1. Stage 2a means the cancer cells has grown into the outer covering of the bowel wall but there are no cancer cells in the lymph nodes (T3, N0, M0)
2. Stage 2b means that the cancer has grown through the outer covering of the bowel wall and into tissues or organs next to the bowel. There are no cancer cells in the lymph nodes, and the cancer has not spread to another area of the body (T4, N0, M0)
Stage 3 Bowel Cancer
This stage is divided into 3 stages
1. Stage 3a means the cancer is still in the inner layer of the bowel wall or has grown into the muscle layer of the bowel wall or has grown into the muscle layer. Between 1 and 3 nearby lymph nodes contain cancer cells (T1, N1, M0 or T2, N1, MO)
2. Stage 3b means the cancer has grown into the outer lining of the bowel wall or into surrounding body tissues or organs. Between 1 and 3 nearby lymph nodes contain cancer cells (T3, N1, M0 or T4, N1, M0)
3. Stage 3c means that the cancer can be any size and has spread to 4 or more nearby lymph nodes. The cancer has not spread to any other part of the body (ant T, N2, M0)
Stage 4 Bowel Cancer
The cancer has spread to other parts of the body (such as the liver and lungs) through the lymphatic system or blood stream (any T, any N, M1)
Grading of Bowel Cancer
As well as the stage of bowel cancer, doctors also consider what the cancer cells look like under microscope ( the grade) when decoding or treatment. The grade tells you how normal or abnormal the cancer cells are. As normal cell grows and matures, it becomes more specialised for its role and plave in the body. This is called differentiation. A pathologist grades bowel cancer as
1. Grade1 (low grade) - the cancer cells are well differentiated, which means they look similar to normal cells.
2. Grade 2 (moderate grade) - the cancer cells are moderately differentiated, which means the cells look more abnormal.
3. Grade 3 (high grade)- The cancer cells are poorly differentiated, which means they look very abnormal.
The grade gives doctors an idea of how the cancer is likely to behave. A low grade cancer is likely to be slower growing and less likely to spread than high grade cancers.
Source: Cancer Research UK
